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Dear Dr. Barchas, I have a 4-year-old indoor Himalayan/Tabby mix who has cat dandruff on the back half of the top of her back. I was wondering what may be the cause of this and what treatment would help. She has had it since she was a kitten, but it pretty much only becomes obvious when I brush her or take her to the vet. My vet has seen it before, so it may not be something to even be concerned about? –Amber

One summer day between my third and fourth years of vet school, I was lazing by the pool at my apartment complex in Davis, California. I may have enjoyed an adult beverage or two. One of the local cats came up to my lounge chair. She was very friendly, but I couldn’t help noticing the massive quantity of white flakes that coated the oily hair on her back. I commented aloud. This is what I said, verbatim: “Holy crap, that’s the worst cat dandruff I’ve ever seen!”

I learned something important that day, and it wasn’t about about feline dermatology. The stranger to my left promptly advised me that she had sought treatment for the cat’s dandruff at several veterinary offices and was told that nothing could be done. The lesson, of course, was to keep my stupid mouth shut.

It should not surprise the reader that veterinary medicine has a term to describe severe dandruff: seborrheic dermatitis. (Given that veterinary medicine even has a term to describe freckles in ginger cats — lentigo simplex — the bigger surprise to me is that there is no special term for putting one’s foot in one’s mouth.) I prefer to call it dandruff.

Amber, cat dandruff is common. It occurs most frequently exactly where you have described: on the back, closer to the tail than to the head. The dandruff may be accompanied by greasy hair.

Most of the time, dandruff, even when severe, is not representative of a disease. However, some skin parasites (particularly one called Demodex) and fungal infections (such as ringworm) can lead to dandruff. So can glandular disorders such as hyperthyroidism, allergies to fleas or food, and even severe problems such as lymphoma. Some cats appear to respond to dermatological insults (such as exposure to chemical irritants) by producing dandruff.

To be sure, you did the right thing by taking your cat to the vet. I hope that she did the appropriate tests to rule out those more serious problems. If she did, it is safe to say that your cat has a good, old-fashioned case of feline dandruff. That means two things. First, the problem will be hard to solve. Second, the problem isn’t a problem and it doesn’t need to be solved.

Feline dandruff is, in my experience, hard to treat. Some vets have touted success with dietary supplements such as omega-3 fatty acids. Others recommend special shampoos or spot-on therapies (specifically, I have seen some vets recommend Douxo Spot On or Alloderm). A few owners have reported success after changing their cats’ diets.

However, most people who own dandruff-laden cats end up frustrated. In my experience, the “problem” does not improve no matter what is done.

I put “problem” in quotes for a reason. If your vet has ruled out serious skin disease, and your cat is not suffering from itching, hair loss, or pain, then as far as your cat is concerned, there is no problem. Cats, unlike humans, don’t worry about first impressions. They don’t obsess in the mirror.

Since the dandruff isn’t bothering your cat, I recommend that you not let it bother you. Why risk gastrointestinal upset from a diet change, or an adverse reaction to a shampoo? The problem isn’t really a problem, so why not do nothing? Veterinary medicine has a fancy term for this as well: benign neglect.